clc;clear;close all;
% x1=-5:.1:5;
% x2=-5:.1:5;
[x1,x2] = meshgrid(-5:.1:5);
y=(x1.^2+x2.^2).^(0.25).*(sin(50*(x1.^2+x2.^2).^(0.1)).^2+1);
surfc(x1,x2,y);
